title: Controlled release from a mechanically-stimulated thermosensitive self-heating composite hydrogel.
abstract: Temperature has been extensively explored as a trigger to control the delivery of a payload from environment-sensitive polymers. The need for an external heat source only allows limited spatiotemporal control over the delivery process. We propose a new approach by using the dissipative properties of a hydrogel matrix as an internal heat source when the material is mechanically loaded. The system is comprised of a highly dissipative hydrogel matrix and thermo-sensitive nanoparticles that shrink upon an increase in temperature. Exposing the hydrogel to a cyclic mechanical loading for a period of 5 min leads to an increase of temperature of the nanoparticles. The concomitant decrease in the volume of the nanoparticles increases the permeability of the hydrogel network facilitating the release of its payload. As a proof-of-concept, we showed that the payload of the hydrogel is released after 5-8 min following the initiation of the mechanical loading. This delivery method would be particularly suited for the release of growth factor as it has been shown that cell receptor to growth factor is activated 5-20 min following a mechanical loading.
authors.affiliation: École Polytechnique Fédérale de Lausanne (EPFL), Institute of Bioengineering, Laboratory of Biomechanical Orthopedics, Switzerland.
authors.forename: Mohamadreza Nassajian
authors.initials: MN
authors.lastname: Moghadam
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Kolesov
authors.forename: Arne
authors.initials: A
authors.lastname: Vogel
authors.forename: Harm-Anton
authors.initials: HA
authors.lastname: Klok
authors.forename: Dominique P
authors.initials: DP
authors.lastname: Pioletti
mesh_terms: D006358:Hot Temperature; D020100:Hydrogels; D010599:Pharmacokinetics; D011102:Polyhydroxyethyl Methacrylate / Q000737:chemistry
chemical_list: D020100:Hydrogels; D011102:Polyhydroxyethyl Methacrylate
keywords: Controlled release; Hydrogel; Mechanical loading; Thermosensitive nanoparticles; Viscous dissipation